The skin's organ system is the?

• A. Integumentary system
• B. Circulatory system
• C. Nervous system
• D. Endocrine system

Answer: (A)

The skin is part of the integumentary system, which includes the skin itself along with hair, nails, and glands. This system protects the body from environment, helps regulate temperature, and provides sensory information, with the skin being its largest organ. The circulatory system governs blood flow and heart function, the nervous system coordinates sensation and control of body activities, and the endocrine system releases hormones through glands. Since the skin and its related structures belong to the integumentary system, that is the correct choice.